AS PSYCHOLOGY NOTES Experimental Designs and HypothesesExperimental DesignsLooking at the letters `RIM' in Experimental R ­ Repeated Measures Design o Participants are involved in more than one condition I ­ Independent Design o Participants are in one condition only. In this design, control groups may be used to ensure the IV caused the effect. M ­ Matched Participants o Participants are matched one or more characteristicsHypothesesThis is a testable statement and they are always paired: 1. Experimental Hypothesis 2. Null HypothesisExperimental Hypothesis Example"That rain will make you grow."This includes an IV (putting people in the rain) and a DV (measuring whether they grow) and alsothe word `that'Null Hypothesis Example"That hitting Paddy will have no significant effect on Jacob and any change will occur purely bychance"This hypothesis states that any change in behaviour is due purely to chance and includes theword `that', an IV (hitting Paddy) and a DV (measuring the effect on Jacob).Directional and Non-directional Hypotheses Directional: Prediction about the directional change Non-directional: No prediction about the directional change 1 AS Level Psychology